Based on the analysis of the Asian lower-level jet stream, this paper indicates that having shifted to the Bay of Bengal, this large-scale lower-level jet(LLJ) develops into two branches: the northern branch (NB) whic...Based on the analysis of the Asian lower-level jet stream, this paper indicates that having shifted to the Bay of Bengal, this large-scale lower-level jet(LLJ) develops into two branches: the northern branch (NB) which is a strong southwest flow moving into the inland of China along the southeast side of the Qinghai-Xizang Plateau and then moving eastward to Japan along the north side of the subtropical high, and the southern branch (SB) which continues to be a west flow and travels into the West Pacific across the Indo-China Peninsula along the south side of the monsoon trough. Above the two branches are two synoptic-scale transient tubular monsoon circulation systems, the northern branch being a subtropical monsoon stream tube (SMST) and the southern branch a tropical monsoon stream tube (TMST). Their ascending branches, corresponding to a subtropical monsoon rain belt and a tropical monsoon rain belt respectively, bear considerable influence on the weather over China.展开更多
Based on the interannual variability of convection over the tropical western North Pacific (WNP), a region of 130°—160°E, 10°—20°N, a composite analysis is performed on the fields of surface temp...Based on the interannual variability of convection over the tropical western North Pacific (WNP), a region of 130°—160°E, 10°—20°N, a composite analysis is performed on the fields of surface temperature, outgoing longwave radiation and 850 hPa zonal wind. The composite results show that the weaker (stronger) WNP convection is related to the El Nino (La Nina)—pattern sea surface temperature (SST) anomalies in the preceding winter and in spring. A comparison with previous results indicates that a similar spatial and temporal distribution of SST anomalies is also associated with the onsets of both the WNP and South China Sea (SCS) monsoons. The composite results also show that the weaker (stronger) convection over the WNP corresponds to the easterly (westerly) anomalies that extend westward from the WNP into the Bay of Bengal. A numerical experiment by an atmospheric general circulation model shows a similar result. In addition, during weaker (stronger) convection summer, the convection over the WNP and lower-level zonal winds over the SCS exhibit a small (large) extent of seasonal evolution.展开更多
In English as Second language reading research, how can the processes involved in reading make contribution to teachingof reading skills has long been discussed. In this essay, processes of reading as well as the appl...In English as Second language reading research, how can the processes involved in reading make contribution to teachingof reading skills has long been discussed. In this essay, processes of reading as well as the applications in the classroom are illus-trated. The first section of this essay will look at some basic or background information about reading process, such as basic con-cepts and importance of lower-level and higher-level processes. The second section will discuss critically lower-level processsuch as word recognition, grammatical knowledge and lexical access. Whether these components of lower-level process have an ef-fect on EFL or ESL advanced learners and how to take these factors into consideration while teaching reading. The third sectionwill talk about several components of higher-level process such as schemata and strategy展开更多
By using ERA-Interim data, the temperature anomaly of the freezing rain and snowstorm event that occurred from Ii to 22 January 2008 in southern China was analyzed. During this period, diabatic heating and temperature...By using ERA-Interim data, the temperature anomaly of the freezing rain and snowstorm event that occurred from Ii to 22 January 2008 in southern China was analyzed. During this period, diabatic heating and temperature advection caused the temperature to increase anomalously over the Tibetan Plateau. The anomalously high temperature moving from the Tibetan Plateau to southern Chin.a played several roles. First, the upper-level subtropical jet over China was split into two parts in the north-south direction, which affected the development of freezing rain in southern China; second, a ridge formed because of the warmer air moving to China, which hindered the transport of cold air from its upstream blocking high, forced the cold air to gather behind the ridge, and facilitated the severe cold air outbreak in the later period of the event; third, an inversion layer formed because of the lower-level cold air and upper-level warmer air over southern China, which was conducive to the development of the event over southern China; and finally, because of the temperature anomaly, opposite wind directions appeared at the lower levels （below 700 hPa）, which helped transport of warm-moist and cold-dry air to the event area.展开更多
Lasing without inversion can be obtained in the medium consisting of atoms of three-level cascade decay system by choosing the incoherently pumping rates if atomic coherence is produced by an external electromagnetic ...Lasing without inversion can be obtained in the medium consisting of atoms of three-level cascade decay system by choosing the incoherently pumping rates if atomic coherence is produced by an external electromagnetic field at two lower levels.Discussions are made on strong external field and resonance cases,respectively.Meanwhile,based on numerical calculations,it is found that a large index of refraction with vanishing absorption and dispersion can be achieved for the probe light of a certain frequency in this medium.展开更多
文摘Based on the analysis of the Asian lower-level jet stream, this paper indicates that having shifted to the Bay of Bengal, this large-scale lower-level jet(LLJ) develops into two branches: the northern branch (NB) which is a strong southwest flow moving into the inland of China along the southeast side of the Qinghai-Xizang Plateau and then moving eastward to Japan along the north side of the subtropical high, and the southern branch (SB) which continues to be a west flow and travels into the West Pacific across the Indo-China Peninsula along the south side of the monsoon trough. Above the two branches are two synoptic-scale transient tubular monsoon circulation systems, the northern branch being a subtropical monsoon stream tube (SMST) and the southern branch a tropical monsoon stream tube (TMST). Their ascending branches, corresponding to a subtropical monsoon rain belt and a tropical monsoon rain belt respectively, bear considerable influence on the weather over China.
基金This study was supported by the " National Key Program for Developing Basic Sciences" G1998040900 Part 1 and the National Natura
文摘Based on the interannual variability of convection over the tropical western North Pacific (WNP), a region of 130°—160°E, 10°—20°N, a composite analysis is performed on the fields of surface temperature, outgoing longwave radiation and 850 hPa zonal wind. The composite results show that the weaker (stronger) WNP convection is related to the El Nino (La Nina)—pattern sea surface temperature (SST) anomalies in the preceding winter and in spring. A comparison with previous results indicates that a similar spatial and temporal distribution of SST anomalies is also associated with the onsets of both the WNP and South China Sea (SCS) monsoons. The composite results also show that the weaker (stronger) convection over the WNP corresponds to the easterly (westerly) anomalies that extend westward from the WNP into the Bay of Bengal. A numerical experiment by an atmospheric general circulation model shows a similar result. In addition, during weaker (stronger) convection summer, the convection over the WNP and lower-level zonal winds over the SCS exhibit a small (large) extent of seasonal evolution.
文摘In English as Second language reading research, how can the processes involved in reading make contribution to teachingof reading skills has long been discussed. In this essay, processes of reading as well as the applications in the classroom are illus-trated. The first section of this essay will look at some basic or background information about reading process, such as basic con-cepts and importance of lower-level and higher-level processes. The second section will discuss critically lower-level processsuch as word recognition, grammatical knowledge and lexical access. Whether these components of lower-level process have an ef-fect on EFL or ESL advanced learners and how to take these factors into consideration while teaching reading. The third sectionwill talk about several components of higher-level process such as schemata and strategy
基金Supported by the National Natural Science Foundation of China(91437215 and 41405055)National Key Basic Research and Development(973)Program of China(2012CB417201)
文摘By using ERA-Interim data, the temperature anomaly of the freezing rain and snowstorm event that occurred from Ii to 22 January 2008 in southern China was analyzed. During this period, diabatic heating and temperature advection caused the temperature to increase anomalously over the Tibetan Plateau. The anomalously high temperature moving from the Tibetan Plateau to southern Chin.a played several roles. First, the upper-level subtropical jet over China was split into two parts in the north-south direction, which affected the development of freezing rain in southern China; second, a ridge formed because of the warmer air moving to China, which hindered the transport of cold air from its upstream blocking high, forced the cold air to gather behind the ridge, and facilitated the severe cold air outbreak in the later period of the event; third, an inversion layer formed because of the lower-level cold air and upper-level warmer air over southern China, which was conducive to the development of the event over southern China; and finally, because of the temperature anomaly, opposite wind directions appeared at the lower levels （below 700 hPa）, which helped transport of warm-moist and cold-dry air to the event area.
文摘Lasing without inversion can be obtained in the medium consisting of atoms of three-level cascade decay system by choosing the incoherently pumping rates if atomic coherence is produced by an external electromagnetic field at two lower levels.Discussions are made on strong external field and resonance cases,respectively.Meanwhile,based on numerical calculations,it is found that a large index of refraction with vanishing absorption and dispersion can be achieved for the probe light of a certain frequency in this medium.
